Understanding a 12v Split Charge Relay Wiring Diagram is crucial for anyone looking to power multiple 12-volt systems in their vehicle, especially for leisure or work applications. This diagram shows you exactly how to connect a split charge relay, a device that intelligently manages power between two separate battery banks. Whether you're setting up a campervan, a mobile workshop, or simply want to ensure your main vehicle battery isn't drained by auxiliary equipment, a proper 12v Split Charge Relay Wiring Diagram is your roadmap to success.
What is a 12v Split Charge Relay and How Does it Work?
A 12v Split Charge Relay Wiring Diagram illustrates a system designed to prevent the discharge of your vehicle's primary starting battery by accessories powered from a secondary leisure battery. In essence, it acts as an automatic switch. When your engine is running, the alternator generates power. The split charge relay senses this increased voltage and connects the leisure battery to the charging system, allowing both batteries to be charged. When the engine is off, the relay disconnects the leisure battery from the starting battery, ensuring that any power drawn by accessories from the leisure battery does not affect the starting power of your vehicle.
The components involved in a typical 12v Split Charge Relay Wiring Diagram are relatively straightforward:
- Main Vehicle Battery: The primary battery used to start the engine.
- Leisure Battery: A secondary battery used to power accessories.
- Split Charge Relay: The intelligent switch that connects/disconnects the batteries.
- Wiring: Appropriate gauge cables to handle the electrical load.
- Fuses: For safety and protection of the circuits.
The importance of a correctly wired split charge system cannot be overstated as it protects your ability to start your vehicle while providing reliable power for your needs. Here's a simplified overview of the connections:
- The relay's trigger terminal is connected to a circuit that is live only when the engine is running (e.g., the ignition live or a terminal on the alternator).
- One of the relay's high-current terminals is connected to the positive terminal of the main vehicle battery.
- The other high-current terminal is connected to the positive terminal of the leisure battery.
- The negative terminals of both batteries are typically earthed to the vehicle's chassis or directly to the vehicle's negative battery terminal.
Here is a table outlining the basic function:
| Condition | Relay State | Battery Connection | Charging Status |
|---|---|---|---|
| Engine Running | Engaged | Main & Leisure Batteries Connected | Both Batteries Charging |
| Engine Off | Disengaged | Main & Leisure Batteries Disconnected | Leisure Battery Powers Accessories Independently |
When you're ready to implement a 12v Split Charge Relay Wiring Diagram, please refer to the comprehensive guide and visual aids provided in the resources that follow this section.